In a patient with suspected lumbar disc prolapse, raising the unaffected leg reproduces pain in the symptomatic opposite limb. What does this crossed straight leg raise test signify?

• A High sensitivity but low specificity for disc herniation
• B Low sensitivity but high specificity for disc herniation ✓
• C It indicates hip pathology rather than spinal pathology
• D It is diagnostic of spinal canal stenosis

Explanation

The crossed straight leg raise (contralateral Lasègue test) has high specificity, around 90 percent, for a large paracentral or central disc herniation, because stretching the healthy root tensions the dural sleeve enough to reproduce contralateral radicular pain. Its sensitivity is low, roughly a quarter to a third of patients. The routine ipsilateral straight leg raise, in contrast, is sensitive but far less specific.

Reference: Apley's System of Orthopaedics and Fractures, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.